Techniques for digital transmission of video promise increased flexibility, higher resolution, and better fidelity. Recent industry collaborations have brought digital video closer to reality; digital video transmission and storage standards have been generated, and consumer digital video products have begun to appear. The move toward digital video has been encouraged by the commercialization of digital technologies in general, such as personal computers and compact discs, both of which have increased consumer awareness of the possibilities of digital technology.
Personal computers, which have recently become common and inexpensive, contain much of the computing hardware needed to produce digital video, including a microprocessor/coprocessor for performing numeric calculations, input and output connections, and a large digital memory for storing and manipulating image data. Unfortunately, personal computers are not suitable for consumer digital video reception, because the microprocessor in a personal computer is a general purpose processor, and typically cannot perform the calculations needed for digital video fast enough to produce full-motion, high definition video output.
Accordingly, there is a need for a special purpose processor particularly suited for performing digital video-related calculations, which can be used as a digital video receiver in consumer applications. Since costs can be most effectively contained by using standard personal computer components where possible, there is a further need for a special purpose microprocessor which facilitates use of commercially available and inexpensive computer components such as digital memory chips. At the same time, however, the special purpose processor must be sufficiently flexible to use any of the available variety of digital memory chips at or near their maximum speed.